. 2016 Apr 19;6:24711. doi: 10.1038/srep24711

Table 3. Summary of environmental variables across 63 sites in the study area.

Environmental vaiables	Mean ± SD	Min-Max	Transformation
Altitude (m)	2309 ± 282.59	1623 ~ 2905	None
Conductivity (μs cm⁻¹)	65.52 ± 30.82	16.80 ~ 151	None
DO (mg L⁻¹)	7.88 ± 0.69	6.52 ~ 10.03	None
pH	7.96 ± 0.24	7.44 ~ 8.55	None
Stream width (m)	2.86 ± 1.69	0.36 ~ 10.70	Log
Depth (m)	0.20 ± 0.08	0.05 ~ 0.45	Log
Mean velocity (m s⁻¹)	0.38 ± 0.22	0.06 ~ 1.27	Squ.root
T-N (mg L⁻¹)	0.27 ± 0.27	0.02 ~ 1.29	Log
NO₃-N (mg L⁻¹)	0.22 ± 0.25	0 ~ 1.12	None
NH₄-N (mg L⁻¹)	0.02 ± 0.01	0.01 ~ 0.07	Log
T-P (mg L⁻¹)	0.01 ± 0.004	0 ~ 0.03	None
PO₄-P (mg L⁻¹)	0.01 ± 0.004	0 ~ 0.02	Log
SiO₂-Si (mg L⁻¹)	4.31 ± 1.41	2 ~ 8.21	Squ.root
TOC (mg L⁻¹)	0.38 ± 0.14	0.15 ~ 0.90	None
Forest %	81.93 ± 13.15	48.66 ~ 96.44	Centred log ratio
Grass %	9.05 ± 7.15	1.32 ~ 32.93	Centred log ratio
Agriculture %	0.52 ± 1.19	0 ~ 6.3	Centred log ratio
Built-up%	3.31 ± 2.40	0.13 ~ 9.32	Centred log ratio
Barren land %	5.19 ± 6.51	0.04 ~ 28.13	Centred log ratio

Transformations applied to meet normality assumptions are listed. None: none transformation; Log: logarithmic transformation; Squ.root: square root transformation; Centred log ratio: a transformation specially for compositional data.